R. Kenova and K. Anguelov and R. Nikolova, Research of the Factors Affecting the Administrative Capacity of Enterprises in the Logistic Sector of Bulgaria. journal = {International Journal of Economics and Management Engineering}, [online]. World Academy of Science, Engineering and Technology. May 2019, vol. 150(6). 814 - 820 [viewed 02 March 2021]. Available from: https://publications.waset.org/pdf/10010460.